Method and system for multi-carrier packet communication with reduced overhead

Abstract

A method and system for minimizing the control overhead in a multi-carrier wireless communication network that utilizes a time-frequency resource is disclosed. In some embodiments, one or more zones in the time-frequency resource are designated for particular applications, such as a zone dedicated for voice-over-IP (VoIP) applications. By grouping applications of a similar type together within a zone, a reduction in the number of bits necessary for mapping a packet stream to a portion of the time-frequency resource can be achieved. In some embodiments, modular coding schemes associated with the packet streams may be selected that further reduce the amount of necessary control information. In some embodiments, packets may be classified for transmission in accordance with application type, QoS parameters, and other properties. In some embodiments, improved control messages may be constructed to facilitate the control process and minimize associated overhead.

What is claimed is: 
     
       1. A method performed by a wireless device in an Orthogonal Frequency Division Multiple Access (OFDMA) wireless system that uses a communication channel that includes contiguous time-frequency resources, wherein the wireless device is capable of receiving data from a network device within a time-frequency resource unit, wherein the time-frequency resource unit is within a resource zone comprising at least some non-contiguous time-frequency resources of the communication channel, the time-frequency resource unit being of a sequential set of time-frequency resource units, each time-frequency resource unit of the sequential set of time-frequency resource units comprising specific contiguous time-frequency resources for receiving signals, the method comprising:
 receiving configuration information associated with the resource zone that determines, for each time-frequency resource unit of the sequential set of time-frequency resource units, a size in time-frequency resources and a sequential position within the resource zone, wherein the time-frequency resources of the resource zone are mapped to the sequential set of time-frequency resource units using the configuration information; 
 receiving control information associated with the time-frequency resource unit, the control information associating a user identifier for the wireless device and a modulation and coding scheme (MCS) with the sequential position of the time-frequency resource unit; and 
 recovering the data based on the user identifier, the MCS, and the associated sequential position. 
 
     
     
       2. The method of  claim 1 , wherein the sequential set of time-frequency resource units comprises a first time-frequency resource unit and a second time-frequency resource unit, the first and second time-frequency resource units having consecutive sequential positions, the specific contiguous time-frequency resources of the first time-frequency resource unit being non-contiguous with the specific contiguous time-frequency resources of the second time-frequency resource unit. 
     
     
       3. The method of  claim 1 , wherein a size of each time-frequency resource unit is pre-defined and shared between the wireless device and the network device; and
 a user identifier and an MCS is associated with the sequential position for each respective time-frequency resource unit. 
 
     
     
       4. The method of  claim 1 , wherein the control information includes a sequence of information elements, each information element of the sequence of information elements including a user identifier and a modulation and coding scheme index, the sequence of information elements including a first information element having the user identifier for the wireless device and an MCS index that identifies the MCS associated with the sequential position of the time-frequency resource unit; and
 wherein the recovering the data is further based at least in part on an association between a position of the first information element in the sequence of information elements and the sequential position of the time-frequency resource unit. 
 
     
     
       5. The method of  claim 4 , wherein the time-frequency resource units of the sequential set of time-frequency resource units are the same length in time. 
     
     
       6. The method of  claim 4 , wherein the wireless device is capable of receiving a plurality of communication channels, each communication channel of the plurality of communication channels having a number of subcarriers based on a width in frequency of the respective communication channel. 
     
     
       7. The method of  claim 4 , wherein the MCS index of each corresponding information element is 4 bits, and wherein each index is selected from a set of MCS indices, wherein the set of MCS indices includes a first MCS index for a ½ coding rate and 16 QAM and a second MCS index for a ½ coding rate and QPSK. 
     
     
       8. The method of  claim 1 , wherein the signals include the data and at least one pilot. 
     
     
       9. The method of  claim 1 , wherein the resource zone comprising non-contiguous time-frequency resources is configured such that:
 at a given time within the non-contiguous time-frequency resources, frequency resources within the time-frequency resources are non-contiguous; or 
 at a given frequency within the non-contiguous time-frequency resources, time resources within the time-frequency resources are non-contiguous. 
 
     
     
       10. The method of  claim 1 , wherein the control information comprises a number of information elements, wherein the number of information elements in the control information is specified by a header and is the same as the number of time-frequency resource units within the sequential set of time-frequency resource units, the information elements being arranged in the same sequential order as the set of sequential time-frequency resource units and each information element being associated with a corresponding time-frequency resource unit and providing a user identifier and identifying an MCS for the corresponding time-frequency resource unit, and wherein each pair of information element and corresponding time-frequency resource unit is associated with a respective sequential position. 
     
     
       11. The method of  claim 1  further comprising:
 classifying packets into a plurality of classes based on quality of service (QoS) requirements of the packets and provide each packet to a respective queue; and 
 selecting and transmitting data from the queues based on the class of the packets. 
 
     
     
       12. The method of  claim 11  wherein the plurality of classes include voice and video, and wherein each of the packets has a header with a type of service (TOS) field, wherein the classifier uses the TOS field to classify the packets. 
     
     
       13. The method of  claim 1 , further comprising:
 receiving uplink configuration information, the uplink configuration information including an information element that identifies the wireless device, indicates a time-frequency resource unit, and indicates a transmission MCS for a transmission by the wireless device to the network device; and 
 transmitting, using OFDMA, data of at least one packet in the transmission to the network device using the indicated time-frequency resource unit and the indicated transmission MCS. 
 
     
     
       14. The method of  claim 13 , wherein:
 the uplink configuration information further includes: broadcasted information and a group of information elements, the group of information elements including the information element that identifies the wireless device and at least one other information element that identifies a different wireless device. 
 
     
     
       15. The method of  claim 13  further comprising classifying packets into a plurality of classes based on quality of service (QoS) requirements of the packets, wherein the indicated time-frequency resource unit is based on a class, of the plurality classes, of the at least one packet. 
     
     
       16. A method performed by a network device in an Orthogonal Frequency Division Multiple Access (OFDMA) wireless system that uses a communication channel that includes contiguous time-frequency resources, wherein the network device is capable of transmitting data to a wireless device within a time-frequency resource unit, wherein the time-frequency resource unit is within a resource zone comprising at least some non-contiguous time-frequency resources of the communication channel, the time-frequency resource unit being of a sequential set of time-frequency resource units, each time-frequency resource unit of the sequential set of time-frequency resource units comprising specific contiguous time-frequency resources for receiving signals, the method comprising:
 transmitting configuration information associated with the resource zone that determines, for each time-frequency resource unit of the sequential set of time-frequency resource units, a size in time-frequency resources and a sequential position within the resource zone, wherein the time-frequency resources of the resource zone are mapped to the sequential set of time-frequency resource units using the configuration information; 
 transmitting control information associated with the time-frequency resource unit, the control information associating a user identifier for the wireless device and a modulation and coding scheme (MCS) with the sequential position of the time-frequency resource unit; and 
 transmitting the data, using the MCS, to the wireless device in the time-frequency resource unit corresponding to the sequential position. 
 
     
     
       17. The method of  claim 16 , wherein the sequential set of time-frequency resource units comprises a first time-frequency resource unit and a second time-frequency resource unit, the first and second time-frequency resource units having consecutive sequential positions, the specific contiguous time-frequency resources of the first time-frequency resource unit being non-contiguous with the specific contiguous time-frequency resources of the second time-frequency resource unit. 
     
     
       18. The method of  claim 16 , wherein a size of each time-frequency resource unit is pre-defined and shared between the wireless device and the network device; and
 a user identifier and an MCS is associated with the sequential position for each respective time-frequency resource unit. 
 
     
     
       19. The method of  claim 16 , wherein the control information includes a sequence of information elements, each information element of the sequence of information elements including a user identifier and a modulation and coding scheme index, the sequence of information elements including a first information element having the user identifier for the wireless device and an MCS index that identifies the MCS associated with the sequential position of the time-frequency resource unit; and
 wherein the transmitting the data is further based at least in part on an association between a position of the first information element in the sequence of information elements and the sequential position of the time-frequency resource unit. 
 
     
     
       20. The method of  claim 19 , wherein the time-frequency resource units of the sequential set of time-frequency resource units are the same length in time. 
     
     
       21. The method of  claim 19 , wherein the network device is capable of transmitting a plurality of communication channels, each communication channel of the plurality of communication channels having a number of subcarriers based on a width in frequency of the respective communication channel. 
     
     
       22. The method of  claim 19 , wherein the MCS index of each corresponding information element is 4 bits, and wherein each index is selected from a set of MCS indices, wherein the set of MCS indices includes a first MCS index for a ½ coding rate and 16 QAM and a second MCS index for a ½ coding rate and QPSK. 
     
     
       23. The method of  claim 16 , wherein the signals include the data and at least one pilot. 
     
     
       24. The method of  claim 16 , wherein the resource zone comprising non-contiguous time-frequency resources is configured such that:
 at a given time within the non-contiguous time-frequency resources, frequency resources within the time-frequency resources are non-contiguous; or 
 at a given frequency within the non-contiguous time-frequency resources, time resources within the time-frequency resources are non-contiguous. 
 
     
     
       25. The method of  claim 16 , wherein the control information comprises a number of information elements, wherein the number of information elements in the control information is specified by a header and is the same as the number of time-frequency resource units within the sequential set of time-frequency resource units, the information elements being arranged in the same sequential order as the set of sequential time-frequency resource units and each information element being associated with a corresponding time-frequency resource unit and providing a user identifier and identifying an MCS for the corresponding time-frequency resource unit, and wherein each pair of information element and corresponding time-frequency resource unit is associated with a respective sequential position. 
     
     
       26. The method of  claim 16  further comprising:
 classifying packets into a plurality of classes based on quality of service (QoS) requirements of the packets and provide each packet to a respective queue; and 
 selecting and transmitting data from the queues based on the class of the packets. 
 
     
     
       27. The method of  claim 26  wherein the plurality of classes include voice and video, and wherein each of the packets has a header with a type of service (TOS) field, wherein the classifier uses the TOS field to classify the packets. 
     
     
       28. The method of  claim 16 , further comprising:
 transmitting uplink configuration information, the uplink configuration information including an information element that identifies the wireless device, indicates a time-frequency resource unit, and indicates an uplink MCS for a transmission by the wireless device to the network device; and 
 receiving, using OFDMA, data of at least one packet in the transmission from the wireless device in the indicated time-frequency resource unit and using the indicated uplink MCS. 
 
     
     
       29. The method of  claim 28 , wherein:
 the uplink configuration information further includes: broadcasted information and a group of information elements, the group of information elements including the information element that identifies the wireless device and at least one other information element that identifies a different wireless device. 
 
     
     
       30. The method of  claim 28 , wherein packets are classified into a plurality of classes based on quality of service (QoS) requirements of the packets, wherein the indicated time-frequency resource unit is based on a class, of the plurality classes, of the at least one packet.